Acne is a very common skin disorder caused by an inflammatory disease of the hair follicles and sebaceous glands. It causes inflammation in the hair follicles of the facial skin of teenagers and young adults. In these days, however, the age distribution of people affected by acne becomes wider and wider due to air pollution, sex hormone unbalance, drug abuse, stress, internal disease, etc. For adolescents, the secretion of male sex hormones (androgens) increases in both boys and girls. These hormones stimulate the sebaceous glands, located next to the hair follicles, and cause them to enlarge and to produce more sebum. At the same time, the surface layer of the skin around the pores becomes thick and sticky, resulting in narrowed or blocked pores. As a result, sebum accumulates within the hair follicles, and bacteria present in the hair follicles multiply, leading to inflammation.
Microorganisms that cause acne and inflammation include Propionibacterium acnes, Staphylococcus aureus, Staphylococcus epidermis, and the like. (Raman A. et al., Lett. Appl. Microbiol., 21: 242-245, 1995). They are also found in the normal skin, and particularly, Propionibacterium acnes is the main bacterium causing acne. These microorganisms enter into the hair follicles through the follicular ducts, and inhabit the hair follicles deep while decomposing sebum to produce free fatty acids. Secondary infection of the infected sites with Staphylococcus strains results in red swelling and pus production.
The antibacterial agents, such as benzoyl peroxide, salicylic acid, benzalkonium chloride, phenol, tetracycline or erythromycin have been used to inhibit bacteria which cause acne and inflammatory skin disease of the hair follicles and sebaceous glands. Although using antibacterial agents such as tetracycline are effective for skin treatment, it has been known to have a high possibility of causing side effects, such as the appearance of strains resistant to Propionibacterium, and photosensitive disorders (Gollnick, H. et al., Dermatology., 196: 119-125, 1998). Furthermore, the salicylic acid preparations mainly effective for the removal of keratin cannot be used for purulent dermatitis and can cause skin flare and erythema. In addition, the benzoyl peroxide preparations for inhibiting pyogenic bacteria are frequently reported to cause side effects, such as allergic dermatitis and erythema, and are known to be unsuccessful in curing acne completely.
Recently, natural substances, such as tea tree oil, royal jelly extract, and ginseng extract, are used to treat acne. However, these natural substances do not comprise a single compound. Thus, other substances added during processes of formulating them into skin external preparations or cosmetics can result in a rapid reduction in the antibacterial activity of the natural substances. Furthermore, the antibacterial spectrum of the natural substances is not so broad that they cannot effectively show antibacterial activity against Staphylococcus strains causing acne. Particularly, the naturally occurring antibacterial substances have a problem in that it is difficult to formulate them, since, upon heating, they lose a large part of their active ingredients by evaporation or have insufficient thermal stability, leading to a rapid reduction in their antibacterial activity (Higaki, S. et al., J. Dermatology., 23: 310-314, 1996).
Lignans are the group of natural substances where n-phenylpropanes are linked by the β-site of n-propyl side chains. Their pharmaceutical effects are known with respect to blood glucose lowering effects (Korean Patent Laid-Open Publication No. 2003-0064919), anti-inflammatory effects (Korean Patent Laid-Open Publication No. 2003-0035124), and the like. Macelignan, a typical lignan compound found in Myristica fragrans (Tuchinda P. et al., Phytochemistry, 59: 169-173, 2002), was reported to have the caspase-3-activating activity of inducing apoptosis (Park B. Y. et al., Biol. Pharm. Bull., 27(8): 1305-1307, 2004), and antioxidative activity (Sadhu, S. K. et al., Chem. Pharm. Bull., 51(9): 595-598, 2003). However, there is still no report on the antibacterial activity of lignan compounds represented by Formula 1, including macelignan, against acne-causing bacteria.